I figures MS was messing with things.
Frequently, when I try to upgrade the MS Essentials virus definitions on both my Win7 laptop and desktop, the little icon spins and never finishes.
To get the new definitions to be recognized, I have to manually download them from MS and ‘Run as Administrator’.
This has been going on for about 6 months.
I have all MS updates turned OFF on both machines. I have too many things that will not run under Win10, so I have no intention of upgrading. I did try it out on an extra hard drive and did not like it at all.
Ever thought about changing antimalware software? Personally, I use ESET. Yes, it's a pay-for but it's very unobtrusive and updates at least twice a day. Small footprint, too.
Between ESET, Malwarebytes and AdwCleaner, I'm able to keep my computer clean. Oh, wiping it with a cloth occasionally helps too :)